Jagdpanzer IV (Sd.Kfz.162) - modified Panzer IV chassis + 7.5 cm Pak 39 L/48 gun. 769~784 were built from Jan 1944 to Nov 1944
Panzer IV/70(V) (Sd.Kfz.162/1) - modified Panzer IV chassis + 7.5cm Pak 42 L/70 gun. The (V) stands for the designer, Vomag (design used a modified chassis permitting a very low silhouette). 930~940 were built from Aug 1944 to Apr 1945. Jagdpanzer IV/70(V) Lang. "Lang" (German for "long") distinguishs it from its predecessor with a shorter L/48 7.5cm gun. The long and powerful 7.5cm Pak 42 L/70 could outrange opposing Allied tank weapons.
Panzer IV/70 (A) (Sd.Kfz.162/1) - standard Panzer IV chassis + 7.5cm Pak 42 L/70 gun. (A)stands for Alkett, a manufacturer of the StuG III, that was ordered to redesign the Jagdpanzer IV superstructure to be mounted onto a standard Panzer IV chassis, requiring additional vertical steel plates mounted onto the chassis to counter height differences. Panzer IV/70 (A) was about 40 cm taller and lacked the sharp edged nose of the Vomag variant. Only 278 were built by Nibelungenwerke from Aug 1944 to Mar 1945.
field improvements - addition of armour sideskirts.
muzzle brake was removed for late production, as the gun was close to the ground, huge dust clouds after shooting would betray the vehicle's position.